Over the weekend, hikers trekking through the Angeles National Forrest near Los Angeles discovered three sets of human remains over the span of two days. Local authorities are unsure about the exact circumstances that led to these skeletons being in the park, but they hypothesize that as El Niño causes heavy rainfall this winter, more bones will be unearthed.

According to Lt. Victor Lewandowsky of the LA Country Sheriff's department, the hand, skull, femur, and spine that were found on Halloween don't appear to have belonged to the same person. Separate investigations have been launched for each set of remains.

“It’s getting everybody’s attention because they start going through their cases. ‘Do I have a missing persons, [or] a foul-play case," Lewandowsky told the Los Angeles Times. "I expect if we [heavy rainfall,] we may see an uptick in stuff that washes down the hill or is unearthed."